Fuse



May 6, 9 J. s. MESSER ET AL FUSE Filed March 31. 1948 a If g b m m m a a w M fl W Z %\w M W n 4 .H W\/ Ji M a 3 JW a 5 i- IT a g E 5am a m 1 (1 $3 24 INVENT0R6- John 5 Wage/3 Patented May 6, 1952 FUSE John S. Messer and David L. Davis, Chicago, 111., assignors, by mesne assignments, to Economy Fuse and Manufacturing 00., Chicago, 111., a corporation of Illinois Application March 31, 1948, Serial No. 18,165

4 Claims. 1

The present invention relates to improvements in fuses.

More particularly, the present invention relates to fuses of the cartridge type having broad fiat terminals located substantially in a single plane.

This application is a continuation in part of the application filed by the present applicants on November 30, 1946, Serial No. 713,358, now Patent No. 2,497,227, which is a continuation in part of the now abandoned application filed by the present applicants on May 30, 1945, Serial No 596,636.

An object of the present invention is to provide a fuse of the kind referred to having sturdy mounting means for said terminals and which may be readily assembled and disassembled for the mounting of a fuse link therein or the removal of the remains of a fuse link.

A further object is to provide a fuse of the kind referred to having the advantage of sturdiness, combined with the advantage that in the event of shrinkage in the enclosing cylinder such shrinkage may be readily compensated for without modifying the proper venting of the fuse.

A further object is to provide a fuse having aligned terminals having the advantage that in the event of shrinkage of the enclosing casing, parts of the fuse may be turned up to compensate for such shrinkage without disturbing the alignment of the terminals.

A further object is to provide a fuse havin an enclosing casing and a fuse holdin unit adapted to be positioned within said enclosing casing in a state of tension, said casing and said fuse holding member having co-operating relatively rocking parts so that in the event of distortion, within limits, the parts may be readily assembled without interfering with the proper venting of the fuse, with the advantage that the fuse terminals will always be positioned in proper alignment with each other.

A further object is to provide a fuse which is sturdy; simple and well adapted to meet the needs of ordinary service.

Further objects will appear as the description proceeds.

Referring to the drawings- Figure 1 is a cross sectional view illustrating a fuse embodying the principles of the present invention;

Figure 2 is a cross sectional view taken along the plane indicated by the arrows 2--2 of Figure 1;

Figure 3 is a cross sectional view taken along the plane indicated by the arrows 3-3 of Fi ure 1;

Figure 4 is a cross sectional view taken along the plane indicated by the arrows 44 of Figure 1;

Figure 5 is a cross sectional view taken along the plane indicated by the arrows 5-5 of Figure 1; and

Figure 6 is a cross sectional view similar to Figure 2 but illustrating a modification embodying mounting means for two fuse links.

Referring first to Figures 1 and 2, the numeral 10 indicates a casing including the cylindrical member 11 of fiber or the like. To one end of said cylindrical member 11 is secured an internally threaded collar 12, said collar having a shoulder disposed internally thereof, against which is bottomed one end of said cylindrical member 11. To accomplish a close fit, the end of the cylindrical member 11 may be threaded into the adjacent end of the collar 12. Rivets 13-13 may be employed to securely hold the cylindrical member 11 and the collar 12 in fixed relationship with each other. The cylindrical member 11 and the collar 12 constitute a cylindrical casing having a threaded extremity. At the other end of the cylindrical member 11 is the annular member 14 having a sleeve portion disposed interiorly of and preferably threaded into the cylindrical member 11, said member 11 being recessed to provide an annular shoulder for receiving an end of said annular member 14. Rivets 13-13 may be employed to securely hold the cylindrical member 11 and the annular member 14 in fixed relationship with each other. Said annular member 14 is threaded exteriorly at the region beyond the adjacent extremity of the cylindrical member I 1.

Disposed within the cylindrical member 11 is the fuse holding unit indicated as a Whole by the numeral 15. Said unit 15 includes the strut or bridge 16, which should be a relatively sturdy member which is non-inflammable and a non-' conductor of electricity. Secured to one, extremity of the strut 16 is the terminal unit 17 including the broad flat blade portion 18 of a form common in cartridge fuses. Said terminal ll includes a tongue portion 18a. The blade portion 18, adjacent to the tongue portion 13a, is defined by the aligned edges 19-19. Said tongue portion 18a is secured to one extremity of the strut 16, drive screws 20 being provided for this purpose. Loosely carried by the fuse holding unit 15 is the externally threaded cupshaped member 2| provided with a plurality of notches 21a-21a spaced around the inner edge of the cylindrical wall thereof and having the bottom wall 22 provided with a slot to receive the tongue portion 18a of the terminal 1?. Located between the adjacent extremity of the strut 16 and the bottom portion 22 of the member 21 is the bafiie plate 22a having a slot for snugly receiving the tongue portion 18a. The slot in the bottom portion 22 is slightly larger than the cross-sectional contour of the tongue portion 18a to permit a slight tilting rocking movement of the cup-shaped member 21 relative to the strut 1B. The strut 16 will preferably be spaced from the aligned edges Iii-19 of the blade portion 18 a distance slightly aeoacee greater than the thickness of the bottom wall 22 plus the thickness of the washer 22a, to provide for play of the membeer 2| and of the washer 22a longitudinally with respect to the strut l6 and the blade portion [8 whereby to facilitate the tilting rocking action just mentioned. Otherwise stated, the member 2| and the baffle plate 22a are mounted upon the terminal I? to have a tilting or universal rocking movement relative to the strut l6 and said terminal H. The bailie plate 22a will have as close a fit with said tongue portion |8a as practicable while permitting such rocking action. The internal diameter of collar I2 is only slightly greater than the width of the blade portion I?) of the terminal ll, whereby said blade portion 18 functions to pilot the threaded cup-shaped member 2! into the internally threaded collar :2. The member 2| may be screwed into the collar l2 indefinitely except as limited by means located at the other end of the strut it, as will appear presently.

The co-operating threads on the member 21 and the collar l2 will be of the type (as, for example, a truncated thread on the member 21) to provide a tortuous passageway permitting the escape of gases from the interior of the fuse when a fuse link blows. As noted above, the member 2! at its inner extremity will be provided with notches 2Ia-2ia extending radially thereacross.

This structure has the advantage of providing a relatively long screw engagement between the member 2! and the collar i2 while permitting access of the gases to the threaded cavity through a plurality of notches 2 la2 a reaching well into the cylindrical wall of the member 2!. The advantage is attained that the escape of gases is permitted without loss of strength in the fuse structure.

The opposite extremity of the strut i is pro vided with the terminal 23, which includes the broad fiat blade portion 24 of usual contour and the tongue portion 2%. The blade portion 24, adjacent to the tongue portion 2%, is defined by the aligned edges 2%. Said tongue portion 2 1a is secured to the adjacent extremity of the strut it by means of drive screws 28-25.

Located between the blade portion of the terminal 23 and the adjacent extremity of the strut 18 are a pair of plates 25 and 26, each of said plates being provided with a slot for receiving the tongue 24a of the terminal 23. The plates 25 and 28 should be capable of a slight tilting rocking movement relative to the tongue portion E ic and the strut it. To accomplish this purpose, the slot in the plate 25 may be slightly larger than the cross-sectional contour of the tongue portion 24a. The slot in the plate 25 should receive the blade portion 2 as'closely as practicable while permitting the rocking movement referred to. The strut it will preferably be spaced from the aligned edges NIP-2417 of the blade portion 24, a distance slightly greater than the thickness of the plate 26 plus the thickness of the plate 25 to provide for play of said plates 25 and 26 longitudinally with respect to the strut t and the blade portion 26 whereby to facilitate the rocking movement just referred to. Otherwise stated, the plates 25 and 2B are mounted upon the terminal 23 to have a tilting or universal rocking movement relative to the strut H5 and said terminal 23. Said plate 25 is shown as being generally triangular in contour, as illustrated in Figure 5, though the triangular contour is not important. Said plate 25 has corner portions adapted to fit within the annular member [4 to hold the fuse holding member I5 in proper alignment within the cylindrical member H. The plate 26 has a diameter greater than the diameter of the plate 25, and the outer portion of said plate is adapted to abut longitudinally against the end of the annular member It to limit screwing movement of the member 2! through the collar !2 and accordingly to limit turning movement of the fuse holding member 15 toward the left with respect to the casing H) as the parts are viewed in Figures 1 and 2.

The numeral 21 indicates an internally threaded collar member adapted to be turned up upon the external screw-threads of the annular member l Said collar 2'! has the end wall 28 adapted 'to abut against the right-hand extremity of the plate 26 as the parts are viewed in Figures 1 and 2.

The right-hand extremity of the annular member i i may be notched as indicated by the numeral 23's. There may be several of these notches to provide passageways from the interior of the cylindrical member I i to the region of the threads on the exterior of the annular member 14 and on the interior of the collar 27. The threads on the member M will be truncated or otherwise designed to co-operate with the thread on the member 27 to provide a tortuous passageway for gases escaping from the interior of the fuse.

A fuse link is indicated by the numeral 2?: and is illustrated as being releasably secured to the tongues lea and 24a of the terminals H and 23, respectively, by means of binding posts 30-33.

The details of the particular fuse link chosen for illustration form no part of the present invention, such details being the invention of Gustav Rensner as disclosed and claimed in his application for United States Letters Patent Serial No. 596,772 filed May 30, 1945, now Patent No. 2,489,501.

Each of the binding posts Bil-30 includes the screw 31 having the head portion Sla adapted to be seated upon the side of the strut IS, the strut being provided with an aperture of sufficient diameter to take freely the shank of the screw 3 l.

The tongue portion 18a and the tongue portion Zia are each provided with a hole 311) threaded for engagement with the thread of the corresponding screw 31. The adjacent extremity of the fuse link 29 is apertured to take freely the shank of the screw 31. A washer Me is adapted to engage the adjacent face of the fuse link 29, and a spring washer 32 and a nut 33 co-operate to removably secure the adjacent extremity of the fuse link 29 in firm electrical contact with the adjacent tongue portion lta or the adjacent tongue portion 24a.

Inasmuch as the head portion am of the screw 31 may be turned down into firm engagement with the strut l6, movement of the corresponding nut 33.will have no practical effect in loosening the screw 3 I from the strut is.

The construction illustrated in Figure 6 need not be described in detail, since it is similar in many respects to the construction illustrated in Figures 1 and 2. It will be sufiicient to state that the fuse holding member 34 includes two struts 3535, which have the terminals H and 23 se cured to their extremities, rivets 350. bein provided for that purpose. Each of said struts 35 is provided with a pair of annular studs 36-35 extending therethrough, said studs having good contact with the corresponding terminals H and 23 and extending beyond the surface of the corresponding strut 34 to provide a good electrical bearing surface for a corresponding fuse link 31. Bolts 38 are provided having broad bearing washers and lock washers for releasably securing said fuse links 37-37 in good electrical contact with the studs 36 and with the corresponding terminals I1, 23.

According to the present invention, the removable fuse holding member I5 of Figures 1 and 2 and the removable fuse holding member 36 of Figure 6 may be readily screwed into the corresponding cylindrical member II, the blade portion I8 of the terminal member I! piloting the cup-shaped member into position in the collar I2, the cup-shaped member 2i having sufi'icient rocking action to find its way readily into the collar I2. The plate 25 having corners conforming to the internal diameter of the annular member I4 will definitely align the fuse holding member with the cylindrical member I I, and the plate 26 engaging the extremity of the annular memher It will definitely limit the inward movement of the movable member into the cylindrical member II The member 21 will be screwed up upon the threaded exterior of the annular member I4 until the flange 23 engages the plat 26. The rockin action of the plates 25 and 26 relative to the strut I6 and the blade portion 24 serves the useful purpose that even though the strut It be bowed, the plates 25 and 26 may seat, respectively, exactly in and on the end of the member I4 to provide the proper seal. The notches 27a in the annular member I4, together with the tortuous course between the external threads on the member I 4 and the internal threads on the member 27, will provide a tortuous passageway permitting the escape of gases from the interior of the fuse when a fuse link blows. The baffle plate 22a, since it has snug engagement with the tongue portion I 8a of the terminal I8, is effective in stopping a violent escape of gas along said tongue portion I8a. The plates 25 and 2S perform a like function with respect to the tongue portion 240, of the terminal 23.

Not only do the illustrated embodiments of the present invention provide sturdiness, convenience and certainty of action, but in addition they have the advantage that in the event of shrinkage of the cylindrical member II, it is only necessary to turn the fuse holding member I5 (Figs, 1 and 2) or 34 (Fig. 6) relative to the cylindrical member II, bringing the plate 26 into engagement with the end of the annular member I l, after which the member 27 may be turned to its home position. The strut I6 and the struts 3535 are always in tension. All adjustments may be made without disturbing the alignment between the terminals I1 and 23.

Though certain preferred embodiments of the present invention have been described in detail, many modifications will occur to those skilled in the art. It is intended to cover all such modifications that fall within the scope of the appended claims.

What is claimed is:

1. A fuse construction embodying a cylindrical casing, one end of said casing having an internally threaded collar secured thereto, an externally threaded cup-shaped member engaged in said collar and being free to move by screwing action therein axially of said casing throughout the limits of engagement of the threading therebetween, a slot in the bottom of said cup-shaped member which forms an end closure for said casing, a baille plate disposed in said cup-shaped member interiorly of said casing adjacent said slot in freemoving relation thereto, a smaller slot in said bafiie plate, a flat terminal element having shoulder portions bearing against the exterior of said cup-shaped member and a tongue contiguous to said shoulder portions extending in loose fitting relation through the slot in said cup-shaped member and in tight fitting relation through the smaller slot in said bailie plate, said terminal and bafile plate having limited universal movement relative to said cup-shaped member during assembly with said collar, and being effective substantially to close the slot in said cup-shaped member as assembled.

2. The invention of claim 1, further including the opposite end of said casing having an externally threaded annular member affixed thereto, a closure plate engaging the end face of said annular member, an internally threaded collar member engaged upon said annular member having a flange to confine and secure said closure plate thereto, a slot in said closure plate, a second baffle plate disposed adjacent said closure plate interiorly of said casing, a smaller slot in said second bafile plate, a second flat terminal element having shoulder portions bearin against the ex terior of said closure plate and a tongue contiguous to said shoulder portion-s extending in loose fitting relation through the slot in said closure plate and in tight fitting relation through the smaller slot in said second baffle plate, said internally threaded collar being turnable relativ to said second flat terminal for screwing action with said annular member during assembly, said second bafiie plate and associated terminal being eifective substantially to close the slot in said closure plate as assembled.

3. The invention of claim 2 in which the tongue portions of said flat terminals oppose each other interiorly of said casing, a strut lying within said casing havin a long dimension that is of less ex tent than the distance between said opposed baffle plates, binding posts connecting said opposed tongues to said strut in spaced relation, and a fuse link bridging said binding posts. I

a. The invention of claim 3 in which said cupshaped member and said annular member are provided with slots communicating with the interior of the casing on the one hand and with their threaded interengaging portions on their associated internally threaded collars, respectively, on the other, said threaded portions being constructed to afiord sinuous passages from the interior to the exterior of said casing for the relief of gaseous pressure therein.

JOHN S. MESSER. DAVID L. DAVIS.

REFERENCES CETED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,231,364 Huxley June 26,1917 1,559,899 La Mar Nov. 3, 1925 1,744,019 Anderson Jan. 14, 1930 1,860,313 La Mar May 2 1, 1932 1,958,366 La Mar May 8, 1934 2,036,177 La Mar Mar. 31, 1936 2,079,097 Wood May 4, 1937 2,113,170 Carney Apr. 5, 1938 2,168,791 Carney Aug. 8, 1939 2,195,147 Grifiith Mar. 26, 1940 2,280,565 Wood 1 Apr. 21., 1942 

